1. Field of the Invention
This invention relates generally to photographic cameras and has particular reference to an improved system for automatically setting the "f" stop of a compact camera during the picture-taking operation.
2. Description of the Prior Art
Photographic cameras having "built-in" devices which automatically control the exposure of the film are well known in the art. For example, "Instamatic" type cameras have been developed which have a fixed shutter speed and a galvanometer type "f" stop control mechanism that is electrically powered by a photoelectric cell or a battery inside the camera. In more recent camera designs, such as the type "X" Instamatic cameras now being marketed by the Eastman Kodak Co. that use percussively fired photoflash lamps, a battery is still employed within the camera to energize the "f" stop control mechanism.
Similar cameras in which the "f" stop or aperture opening is automatically regulated by means of a battery-powered galvanometer system that includes a light-sensitive resistor as part of the control circuit are also known in the art.
The need for a battery in such cameras constitutes a serious drawback and creates problems for the photographer since film exposure will not be properly controlled unless the battery provides the required amount of electrical energy. Hence, a faulty or weak battery would render the "f" stop control system inoperative or erratic . . . either of which would result in incorrect exposure of the film. Dirty or oxidized battery contacts would also interfere with the proper operation of the "f" stop control system. All of these problems are eliminated by the improved "f" stop control and power system of the present invention.